Although the packaging of many types of commodities and food products has been highly automated, packaging of some commodities is yet fairly labor intensive. Moreover, many of these processes give rise to significant waste.
By way of example, in a common method for packaging turkey roasts, three whole muscle turkey breasts are manually arranged to gain the desired muscle alignment and then stuffed into a transparent bag by a worker. The mouth of the bag then is manually twisted and clamped shut with a mechanical fastener. The region of the bag adjacent the bag opening inherently comes into contact with the emulsion-laden turkey pieces as they are inserted into the bag. This contamination of the bag opening makes it very difficult, if not impossible, to heat seal the bag--many heat sealing machines are capable of sealing bags that are merely wet, but the emulsion on the bag is particularly difficult in that it may both foul the actual seal and it may contaminate the sealing device surfaces, building up a residue that prevents the machine from working properly. Thus, such emulsion laden bags typically are fastened with a metal or similar mechanical fastening device, which does not produce a moisture-tight closure.
Turkey roasts of the type just described often (though not necessarily) are pre-cooked in these packaged bags. Because the mechanical-type closure is not moisture tight, and because the manual packaging process makes it difficult to evacuate all air pockets, the bags typically include small perforations uniformly distributed about the bag to permit trapped air to escape during the roasting process. These holes also permit the natural juices to escape, however, both before, during, and after the cooking process. Moreover, the manual packaging of such roasts inevitably leads to waste in the loss of small pieces of meat and of juices, and is physically difficult due to the laborious and repetitive motions involved in tightly stuffing the muscles and manually expelling as much air as is reasonably possible.